Link Between Bilingualism and Prevention of Alzheimer’s Disease

Summary
Studies have shown that the elderly who are socially, mentally and physically more active have a certain amount of protection from age-related memory loss and other loss of cognitive skills and abilities. This study attempted to see if the use of two languages could provide such protection to the elderly. The results showed that those who were bilingual had the beginning of symptoms of cognitive and memory loss on an average of five years after those who were monolingual. It was found that other factors like occupation, education, and immigration status did not affect the results.

Introduction
Studies have shown that cognitive and mental skills and faculties deteriorate with age and the elderly who are physically, mentally and socially active are protected to a certain extent from this type of deterioration. However, it is not known whether it is these activities or other factors like genetics, level of education, and the occupational status of the individuals’ aid in preserving their cognition. Knowledge of two languages is often an occupation or immigration necessity and does not have a direct link with the educational status or other factors. Thus, the researchers attempted to investigate if bilingual people were better protected against age-related memory and cognitive loss, compared to those who were monolingual.

Methodology
* The study, which was conducted from January 2007 to December 2009, included 211 patients with a possible risk of Alzheimer’s disease (AD).
* All the relevant data on the patients including the age at diagnosis, age at beginning of symptoms, occupation, educational status, knowledge, and fluency in English and other languages were recorded.
* For this study, bilingualism was defined as having spent most of the life regularly using at least two languages.

Data/Results/Key findings
* According to the criteria for this study, 102 patients were termed bilingual and 109 patients were termed monolingual. Yiddish, Polish, Italian, Hungarian, and French were found to be the commonest second languages, next to English.
* The results showed that those who were bilingual had their diagnosis of AD an average of 4.3 years after those who were monolingual. Their symptom onset was also 5.1 years delayed when compared to monolingual patients.
* Both the monolingual and bilingual groups appeared to be similar in other features like occupation, cognitive skills, gender, and immigration status. However, monolingual patients had more formal education than bilingual patients did. These factors did not significantly affect the time of onset of symptoms and diagnosis in both groups of patients.

Next steps/Shortcomings
The authors agree that this study examined patients with a probable diagnosis. They suggest further studies that follow large populations with mono or bilingualism and detect the number of people in each group that develop AD or other memory and cognitive damage. The authors confirm that this study found that educational status was seen to be higher in monolingual patients. This was contrary to what was expected.

Conclusion
This study confirms that intellectual activity in terms of bilingualism, which was found in previous studies, may offer some protection against the beginning of symptoms and diagnosis of AD. This study also shows that this effect is free of associations with other factors like occupation, education, and immigration. However, the authors suggest that most of their bilinguals were immigrants and possibly thus, more active. This may have contributed to these results. The authors conclude that they “are not claiming that bilingualism in any way prevents AD or other dementias; the available evidence does suggest, however, that bilingualism postpones the onset of symptoms.” The authors also suggest further studies to be conducted with regard to the onset and prevalence of AD in countries that have high rates of bilingualism.

For More Information:Delaying the Onset of Alzheimer DiseasePublication Journal: Neurology, November 2010By Fergus I M Craik, PhD; Ellen Bialystok, PhDFrom the University of Toronto, Ontario, Canada